CN118435529A

CN118435529A - Method and apparatus for transmitting and receiving signals in a communication system

Info

Publication number: CN118435529A
Application number: CN202280085180.0A
Authority: CN
Inventors: 韩镇百; 徐永吉; 洪义贤; 金范峻; 权净炫; 崔琬
Original assignee: Hyundai Motor Co; SNU R&DB Foundation; Kia Corp
Current assignee: Hyundai Motor Co; SNU R&DB Foundation; Kia Corp
Priority date: 2021-12-21
Filing date: 2022-12-21
Publication date: 2024-08-02
Also published as: KR20230095035A; WO2023121322A1; US20240348309A1; US12413284B2

Abstract

A method for operating a first communication node in an embodiment of a communication system may comprise the steps of: determining a transmission candidate antenna group including one or more transmission antenna elements from among a plurality of transmission antenna elements constituting a first transmission antenna of a first communication node, via which wireless signals can be transmitted in a direction of a second communication node through a first lens; receiving information on a reception candidate antenna group from a second communication node; determining one or more antenna element combinations based on one or more transmit antenna elements included in the transmit candidate antenna group and one or more receive antenna elements included in the receive candidate antenna group; and performing wireless communication with the second communication node based on the one or more antenna element combinations.

Description

Method and apparatus for transmitting and receiving signal in communication system

Technical Field

The present invention relates to a signal transmission and reception technique in a communication system, and more particularly, to a signal transmission and reception technique for improving beam transmission and reception performance based on multiple-input multiple-output (MIMO) in a high frequency band.

Background

With the development of information and communication technologies, various wireless communication technologies are being developed. Representative wireless communication technologies include long-term evolution (LTE) and New Radio (NR), which are defined as the third generation partnership project (3rd generation partnership project,3GPP) standard. LTE may be one of the fourth generation (4th generation,4G) wireless communication technologies and NR may be one of the fifth generation (5th generation,5G) wireless communication technologies.

To handle the fast growing wireless data, 5G NR communication or subsequent wireless communication techniques may support relatively high frequency band communication. For example, radio bands used for wireless communication can be roughly divided into a frequency range 1 (fr 1) band and a frequency range 2 (fr 2) band. Here, the FR1 band may refer to a relatively low frequency band below about 7 GHz. The FR2 band may refer to a relatively high frequency band above about 7 GHz.

In relatively high frequency bands, such as the 24-53GHz band (corresponding to the FR2 band), unlicensed bands, and millimeter wave bands, relatively high levels of path loss may occur. In an exemplary embodiment of a communication system using a high frequency band, the path loss problem may be solved by transmitting and receiving wireless signals (or beams) having a high antenna gain using a large number of antennas.

In an ultra-high frequency band such as a terahertz wave band, it may be necessary to utilize a very large number of antennas to improve communication quality. As the number of antennas used for communication increases, the overhead and/or computational effort required for communication may increase. Techniques for improving efficiency in performing beam-based communications with a large number of antennas may be needed in relatively high frequency bands.

The matters described as the prior art are prepared for promoting an understanding of the background of the invention and may include matters not yet known to a person of ordinary skill in the art to which the exemplary embodiments of the invention pertain.

Disclosure of Invention

Technical problem

The present invention has been made in an effort to provide a signal transmission and reception method and apparatus for improving MIMO-based beam transmission and reception performance, in which radio signals are transmitted and received with a large number of antennas in a high frequency band.

Technical proposal

The method of operating a first communication node according to an exemplary embodiment of the present invention for achieving the above object may include: determining a first lens to be applied to a first transmit antenna of a first communication node; identifying a first transmission direction to a second communication node of the communication system; determining a transmission candidate antenna group among a plurality of transmission antenna elements constituting a first transmission antenna, the transmission candidate antenna group including one or more transmission antenna elements capable of transmitting a wireless signal in a first transmission direction through a first lens; receiving information on a reception candidate antenna group from a second communication node; determining one or more antenna element combinations based on one or more transmit antenna elements included in the transmit candidate antenna group and one or more receive antenna elements included in the receive candidate antenna group; and performing wireless communication with the second communication node based on the one or more antenna element combinations.

One or more transmit antenna elements included in the transmit candidate antenna group may be selected based on a first transmit antenna element corresponding to a first transmit angle determined according to the first transmit direction and the first lens.

The first transmission direction may be identified based on the location information of the first communication node, and one or more reception antenna elements included in the reception candidate antenna group may be selected based on a first reception antenna element determined based on a first reception direction of the first communication node identified at the second communication node and a first incident angle determined according to a second lens of the first reception antenna applied to the second communication node.

Each of the one or more antenna element combinations may include at least one transmit antenna element corresponding to a number of transmit antenna elements that are available at the same time as a first communication node included in one or more transmit antenna elements in the transmit candidate antenna group and at least one receive antenna element corresponding to a number of receive antenna elements that are available at the same time as a second communication node included in one or more receive antenna elements in the receive candidate antenna group.

Performing wireless communication with the second communication node may include: information regarding one or more antenna element combinations is transmitted to the second communication node, wherein the information regarding the one or more antenna element combinations may indicate a combination index corresponding to each of the one or more antenna element combinations and a mapping relationship between at least one transmit antenna element and at least one receive antenna element.

Performing wireless communication with the second communication node may include: transmitting information about one or more antenna element combinations to a second communication node; performing a first measurement procedure with the second communication node based on the information about the one or more antenna element combinations; identifying a received strength corresponding to each of the one or more antenna element combinations based on the first measurement procedure; and determining a priority of each of the one or more antenna element combinations based on the received strength corresponding to each of the one or more antenna element combinations.

Performing wireless communication with the second communication node may include: a reselection indicator is received from the second communication node, the reselection indicator indicating whether a reselection procedure for one or more combinations of antenna elements is required, wherein the reselection procedure may be triggered when the reselection indicator indicates that a reselection procedure is required.

Determining the first lens may include: identifying information about a first reference frequency for determining a lens to be applied to a first transmit antenna; and determining the first lens based on the information about the first reference frequency and the information about the first frequency for communicating with the second communication node.

The method of operation may further comprise: transmitting, to the second communication node, a first indication comprising information about the second reference frequency for determining a lens of a first receiving antenna to be applied to the second communication node, prior to receiving the information about the set of receiving candidate antennas; and transmitting first scheduling information comprising information about a first frequency for communication with the second communication node, wherein the information about the second reference frequency and the information about the first frequency may be used to determine a second lens to be applied to a first receive antenna in the second communication node.

The method of operating a first communication node according to an exemplary embodiment of the present invention for achieving the above object may include: determining a first lens to be applied to a first receive antenna of a first communication node; identifying a first reception direction of a second communication node of the communication system; determining a reception candidate antenna group among a plurality of reception antenna elements constituting a first reception antenna, the reception candidate antenna group including one or more reception antenna elements capable of receiving a wireless signal received at the first reception antenna in a first reception direction through a first lens; transmitting information about the reception candidate antenna group to the second communication node; receiving information from the second communication node regarding one or more antenna element combinations determined based on one or more receive antenna elements included in the receive candidate antenna group and one or more transmit antenna elements included in the transmit candidate antenna group determined by the second communication node; and performing wireless communication with the second communication node based on the one or more antenna element combinations.

One or more transmit antenna elements included in the transmit candidate antenna group may be selected based on a first transmit antenna element corresponding to a first transmit angle determined based on a first transmit direction to the first communication node identified at the second communication node and a second lens of the first transmit antenna to be applied to the first communication node.

One or more receiving antenna elements included in the receiving candidate antenna group may be selected based on the first receiving antenna element corresponding to the first incident angle determined according to the first receiving direction and the first lens.

Each of the one or more antenna element combinations may include at least one transmit antenna element corresponding to a number of transmit antenna elements that are available at the same time as a second communication node included in the one or more transmit antenna elements in the transmit candidate antenna group and at least one receive antenna element corresponding to a number of receive antenna elements that are available at the same time as a first communication node included in the one or more receive antenna elements in the receive candidate antenna group.

Performing wireless communication with the second communication node may include: performing a first measurement procedure with the second communication node based on the information about the one or more antenna element combinations; identifying a received strength corresponding to each of the one or more antenna element combinations based on the first measurement procedure; and transmitting information about a reception intensity corresponding to each of the one or more antenna element combinations to the second communication node.

Performing wireless communication with the second communication node may include: a reselection indicator is sent to the second communication node, the reselection indicator indicating whether a reselection procedure for one or more combinations of antenna elements is required, wherein the reselection procedure may be triggered when the reselection indicator indicates that a reselection procedure is required.

Transmitting the reselection indicator may include: identifying a reception intensity corresponding to each of the one or more antenna element combinations; performing a determination of whether a reselection procedure is required based on the received strength corresponding to each of the one or more antenna element combinations; generating a reselection indicator based on a result of the determination of whether the reselection process is required; and transmitting the generated reselection indicator to the second communication node.

A transmitting node according to an exemplary embodiment of the present invention for achieving the above object may include a processor which may cause the transmitting node to perform: determining a first lens to be applied to a first transmit antenna of a transmit node; identifying a transmission direction to a plurality of receiving nodes of the communication system, respectively; determining a transmission candidate antenna group among a plurality of transmission antenna elements constituting a first transmission antenna, the transmission candidate antenna group including one or more transmission antenna elements capable of transmitting a wireless signal in a transmission direction through a first lens; receiving information on a reception candidate antenna group from a plurality of reception nodes; determining one or more antenna element combinations based on one or more transmit antenna elements included in the transmit candidate antenna group and one or more receive antenna elements included in the receive candidate antenna group; and performing wireless communication with the receiving node based on the one or more antenna element combinations.

Each of the one or more antenna element combinations may include at least one transmit antenna element corresponding to a number of transmit antenna elements that are available at the same time as a transmit node included in one or more transmit antenna elements in the transmit candidate antenna group and at least one receive antenna element corresponding to a number of receive antenna elements that are available at the same time as a receive node included in one or more receive antenna elements in the receive candidate antenna group.

In performing wireless communications with the receiving node, the processor may further cause the transmitting node to perform: transmitting information about one or more antenna element combinations to a receiving node; performing a first measurement procedure with the receiving node based on the information about the one or more antenna element combinations; identifying reception intensities respectively corresponding to one or more antenna element combinations based on the first measurement procedure; and determining respective priorities of the one or more antenna element combinations based on received intensities respectively corresponding to the one or more antenna element combinations.

Upon determining the first lens, the processor may further cause the transmitting node to perform: identifying Doppler shift (doppler shift, DS) information and delay requirement (latency requirement, LR) information for each receiving node; and determining respective priorities of the one or more antenna element combinations based on the reception intensities respectively corresponding to the one or more antenna element combinations, the DS information of each reception node, and the LR information of each reception node.

Advantageous effects

According to the method and apparatus for transmitting and receiving signals in a communication system, MIMO-based beam transmission and reception performance for transmitting and receiving wireless signals using a large number of antennas in a high frequency band can be improved. In a communication system, a transmitting node and a receiving node that transmit and receive wireless signals using lens MIMO structured antennas may determine a transmission candidate antenna group and a reception candidate antenna group based on the results of mutual wireless signal transmission and reception. The transmitting node and the receiving node may determine one or more antenna element combinations based on the transmission candidate antenna group and the reception candidate antenna group, and may perform wireless communication with each other based on the determined antenna element combinations. Thus, the transmitting node and the receiving node can determine the optimal transmitting direction and receiving direction for mutual communication.

Drawings

Fig. 1 is a conceptual diagram illustrating an exemplary embodiment of a communications system.

Fig. 2 is a block diagram illustrating an exemplary embodiment of a communication node constituting a communication system.

Fig. 3 is a conceptual diagram for describing a first exemplary embodiment of an antenna configuration in a communication system.

Fig. 4 is a conceptual diagram for describing a second exemplary embodiment of an antenna configuration in a communication system.

Fig. 5a and 5b are conceptual diagrams for describing an exemplary embodiment of a communication method based on a second exemplary embodiment of an antenna configuration in a communication system.

Fig. 6 is a sequence diagram for describing a first exemplary embodiment of a signal transmission and reception method in a communication system.

Fig. 7 is a flowchart for describing a second exemplary embodiment of a signal transmission and reception method in a communication system.

Fig. 8 is a flowchart for describing a third exemplary embodiment of a signal transmission and reception method in a communication system.

Fig. 9 is a sequence diagram for describing a fourth exemplary embodiment of a signal transmission and reception method in a communication system.

Fig. 10 is a flowchart for describing a fifth exemplary embodiment of a signal transmission and reception method in a communication system.

Fig. 11 is a flowchart for describing a sixth exemplary embodiment of a signal transmission and reception method in a communication system.

Detailed Description

While the invention is susceptible to various modifications and alternative forms, specific exemplary embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals refer to like elements throughout the description of the drawings.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a similar fashion (i.e., "between … …" versus "directly between … …", "adjacent" versus "directly adjacent", etc.).

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including," when used herein, specify the presence of stated features, values, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, values, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

A description will be given of a communication system to which an exemplary embodiment according to the present invention is applied. The communication system to which the exemplary embodiments according to the present invention are applied is not limited to the following description, and the exemplary embodiments according to the present invention may be applied to various communication systems. Here, the communication system may have the same meaning as the communication network.

Throughout the present invention, the network may include, for example, a wireless internet such as wireless fidelity (WIRELESS FIDELITY, wiFi), a mobile internet such as wireless broadband internet (wireless broadband Internet, wiBro) or microwave access world interoperability (world interoperability for microwave access, wiMax), a 2G mobile communication network such as global system for mobile communication (GSM) or code division multiple access (code division multiple access, CDMA), a 3G mobile communication network such as wideband code division multiple access (wideband code division multiple access, WCDMA) or CDMA2000, a 3.5G mobile communication network such as high speed downlink packet access (HIGH SPEED downlink PACKET ACCESS, HSDPA) or high speed uplink packet access (HIGH SPEED uplink PACKET ACCESS, HSUPA), a 4G mobile communication network such as long term evolution (long term evolution, LTE) network or LTE-Advanced network, a 5G mobile communication network, a B5G mobile communication network (6G communication network, etc.).

Throughout the present invention, a terminal may refer to a mobile station, mobile terminal, subscriber station, portable subscriber station, user device, access terminal, etc., and may include all or part of the functionality of a terminal, mobile station, mobile terminal, subscriber station, mobile subscriber station, user device, access terminal, etc.

Here, the following devices with communication capability may be used as terminals: desktop computers, laptop computers, tablet computers, wireless telephones, mobile phones, smart watches, smart glasses, electronic book readers, portable multimedia players (portable multimedia player, PMP), portable game consoles, navigation devices, digital cameras, digital multimedia broadcast (digital multimedia broadcasting, DMB) players, digital audio recorders, digital audio players, digital picture recorders, digital picture players, digital video recorders, digital video players, and the like.

Throughout the present invention, a base station may refer to an access point, a radio access station, a Node B (NB), an evolved node B (evolved node B), a base transceiver station, a mobile multi-hop relay (mobile multihop relay, MMR) -BS, etc., and may include all or part of the functionality of a base station, an access point, a radio access station, a NB, an eNB, a base transceiver station, an MMR-BS, etc.

Hereinafter, preferred exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, for the convenience of general understanding, the same reference numerals are used for the same elements in the drawings, and repeated description of the same elements is omitted.

As shown in fig. 1, communication system 100 may include a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. In addition, the communication system 100 may further include a core network (e.g., a serving gateway (SERVING GATEWAY, S-GW), a packet data network gateway (PDN (PACKET DATA network) -gateway, P-GW), and a mobility management entity (mobility MANAGEMENT ENTITY, MME)). When the communication system 100 is a 5G communication system (e.g., new Radio, NR) system), the core network may include access and mobility management functions (ACCESS AND mobility management function, AMF), user plane functions (user plane function, UPF), session management functions (session management function, SMF), and the like.

The plurality of communication nodes 110 to 130 may support communication protocols (e.g., LTE communication protocol, LTE-a communication protocol, NR communication protocol, etc.) defined in the third generation partnership project (3rd generation partnership project,3GPP) technical specification. The plurality of communication nodes 110 to 130 may support a code division multiple access (code division multiple access, CDMA) based communication protocol, a Wideband CDMA (WCDMA) based communication protocol, a time division multiple access (time division multiple access, TDMA) based communication protocol, a frequency division multiple access (frequency division multiple access, FDMA) based communication protocol, an orthogonal frequency division multiplexing (orthogonal frequency division multiplexing, OFDM) based communication protocol, a filtered OFDM based communication protocol, a cyclic prefix OFDM (CP-OFDM) based communication protocol, a discrete fourier transform spread OFDM (discrete Fourier transform-spread-OFDM, DFT-s-OFDM) based communication protocol, an orthogonal frequency division multiple access (orthogonal frequency division multiple access, OFDMA) based communication protocol, a single carrier FDMA (SINGLE CARRIER FDMA, SC-FDMA) based communication protocol, a non-orthogonal multiple access (non-orthogonal multiple access, NOMA) based communication protocol, a universal frequency division multiplexing (generalized frequency division multiplexing, GFDM) based communication protocol, a filter bank multicarrier (filter bank multi-carrier, FBMC) based communication protocol, a universal filtered multicarrier (universal filtered multi-carrier) based communication protocol, a Spatial Division Multiple Access (SDMA) based communication protocol, etc. Each of the plurality of communication nodes may have the following structure.

As shown in fig. 2, the apparatus 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to a network for performing communication. In addition, the apparatus 200 may further include an input interface device 240, an output interface device 250, a storage device 260, and the like. The various components included in apparatus 200 may communicate with one another when connected by bus 270.

The processor 210 may execute programs stored in at least one of the memory 220 and the storage 260. Processor 210 may refer to a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), or a special-purpose processor on which methods according to embodiments of the present invention are performed. Each of the memory 220 and the storage 260 may be composed of at least one of a volatile storage medium and a nonvolatile storage medium. For example, the memory 220 may include at least one of Read Only Memory (ROM) and Random Access Memory (RAM).

Referring again to fig. 1, the communication system 100 may include a plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 and a plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell (macro cell), and each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell (SMALL CELL). The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the cell coverage of the first base station 110-1. In addition, the second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the cell coverage of the second base station 110-2. In addition, the fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong to the cell coverage of the third base station 110-3. In addition, the first terminal 130-1 may belong to the cell coverage of the fourth base station 120-1, and the sixth terminal 130-6 may belong to the cell coverage of the fifth base station 120-2.

Herein, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be referred to as a Node B (NB), an evolved node B (eNB), a gNB, an advanced base station (advanced base station, ABS), a high reliability base station (HR-BS), a base transceiver station (base transceiver station, BTS), a radio base station, a radio transceiver, an access point (access point), an access node, a radio access station (radio access station, RAS), a mobile multi-hop relay station (mobile multihop relay-base station, MMR-BS), a Relay Station (RS), an advanced relay station (ADVANCED RELAY station, ARS), a high reliability relay station (HR-RS), a home node B (home eNodeB, heNB), a roadside unit (road de unit, RSU), a radio transmitter (radio remote head, TP), a remote control station (TRP) and the like.

Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may be referred to as a User Equipment (UE), a terminal device (terminal equipment, TE), an advanced mobile station (advanced mobile station, AMS), a high reliability-mobile station (HR-MS), a terminal, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, an on-board unit (OBU), and the like.

On the other hand, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in the same frequency band or different frequency bands. The plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to each other via an ideal backhaul link (ideal backhaul link) or a non-ideal backhaul link and exchange information with each other via an ideal or non-ideal backhaul. In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to the core network through an ideal backhaul link or a non-ideal backhaul link. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may transmit a signal received from the core network to a corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6, and transmit a signal received from a corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 to the core network.

Further, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may support multiple-input multiple-output (MIMO) transmission (e.g., single-user MIMO, SU-MIMO, multi-user MIMO, MU-MIMO, massive MIMO, etc.), coordinated multi-point (coordinated multipoint, coMP) transmission, carrier aggregation (carrier aggregation, CA) transmission, transmission in an unlicensed band, device-to-device (D2D) communication (or proximity services (proximity service, proSe)), internet of things (Internet of Things, ioT) communication, dual connectivity (dual connectivity, DC), etc. Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may perform operations corresponding to the operations of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2, operations supported by the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and the like. For example, the second base station 110-2 may transmit signals to the fourth terminal 130-4 in SU-MIMO mode, and the fourth terminal 130-4 may receive signals from the second base station 110-2 in SU-MIMO mode. Alternatively, the second base station 110-2 may transmit signals to the fourth and fifth terminals 130-4 and 130-5 in a MU-MIMO manner, and the fourth and fifth terminals 130-4 and 130-5 may receive signals from the second base station 110-2 in a MU-MIMO manner.

Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may transmit signals to the fourth terminal 130-4 in CoMP transmission, and the fourth terminal 130-4 may receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 in CoMP transmission. Furthermore, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may exchange signals with a corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 belonging to its cell coverage in a CA manner. Each of the base stations 110-1, 110-2, and 110-3 may control D2D communication between the fourth terminal 130-4 and the fifth terminal 130-5, and thus the fourth terminal 130-4 and the fifth terminal 130-5 may perform D2D communication under the control of the second base station 110-2 and the third base station 110-3.

Hereinafter, a signal transmission and reception method in the communication system will be described. Even when a method (e.g., transmission or reception of a data packet) performed at a first communication node among the communication nodes is described, the corresponding second communication node can perform a method (e.g., reception or transmission of a data packet) corresponding to the method performed at the first communication node. That is, when describing the operation of the terminal, the corresponding base station may perform an operation corresponding to the operation of the terminal. In contrast, when describing the operation of the base station, the corresponding terminal may perform an operation corresponding to the operation of the base station.

As shown in fig. 3, communication system 300 may support multiple-input multiple-output (MIMO) based communication. Communication system 300 may include one or more communication nodes that transmit and/or receive wireless signals. One or more communication nodes included in communication system 300 may be the same or similar to the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 and the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 described with reference to fig. 1. Each of the one or more communication nodes included in communication system 300 may be the same or similar to communication node 200 described with reference to fig. 2. Each of the one or more communication nodes included in communication system 300 may include one or more antennas capable of transmitting and/or receiving wireless signals based on MIMO.

For example, the communication system 300 may include a first antenna 310. The first antenna 310 may support MIMO. The first antenna 310 may be composed of n antenna elements 311-1, … …, and 311-n (n is a natural number). The n antenna elements 311-1, … …, and 311-n constituting the first antenna 310 may be regularly or irregularly arranged.

In an exemplary embodiment of the communication system 300, the first antenna 310 may have a uniform linear array (ULA LINEAR ARRAY) structure. In the first antenna 310 having the ULA structure, the antenna elements 311-1, … …, and 311-n may be arranged in a row at regular intervals.

On the other hand, in another exemplary embodiment of the communication system 300, the first antenna 310 may have a Uniform Planar Array (UPA) structure. In the first antenna 310 having the UPA structure, the antenna elements 311-1, … …, and 311-n may be arranged in a mesh structure at regular intervals on a plane.

In an exemplary embodiment of the communication system, antenna ports and/or antenna plates may be defined to improve the operating efficiency of MIMO-enabled antennas. For example, the first antenna 310 may be comprised of one or more antenna ports, each comprised of one or more antenna elements having the same channel. The first antenna 310 may have a single-panel antenna structure or a multi-panel antenna structure.

In an exemplary embodiment of the communication system, the antenna port may be configured as a basic unit of an antenna structure. An antenna port may be defined as one logical antenna that is made up of one or more antenna elements (or antennas) with the same channel. The channel of a particular symbol transmitted from one antenna port may be inferred from the channel of another symbol transmitted by the same antenna port.

For example, the channel transmitting the physical downlink shared channel (physical downlink SHARED CHANNEL, PDSCH) symbols for one antenna port may be inferred from the channel transmitting demodulation reference symbols (demodulation-REFERENCE SYMBOL, DM-RS) associated with PDSCH symbols by the same antenna port. The channel that transmits the physical downlink control channel (physical downlink control channel, PDCCH) symbol of one antenna port may be inferred from the channel that the DM-RS associated with the PDCCH symbol is transmitted by the same antenna port. The channel that transmits the physical broadcast channel (physical broadcast channel, PBCH) symbol of one antenna port may be inferred from the channel that the DM-RS associated with the PBCH symbol is transmitted by the same antenna port.

If the massive nature of the channel over which symbols are transmitted by one antenna port can be estimated or inferred from the channel over which symbols of the other antenna port are transmitted, two different antenna ports can be denoted as quasi co-located (QCLed). Here, the large-scale characteristics of the channel may include one or more of "delay spread", "doppler shift", "average gain", "average delay", or "spatial Rx parameter".

A structure in which all of one or more antenna elements (or antennas) constituting one antenna structure are present on one panel may be referred to as a "single panel antenna structure". On the other hand, a structure in which a plurality of antenna elements (or antennas) constituting one antenna structure exist in such a manner as to be divided over a plurality of plates may be referred to as a "multi-plate antenna structure". The multi-panel antenna structure may have advantages such as high power gain and low computational complexity.

In an ultra-high frequency band such as a terahertz wave band, it may be necessary to utilize a very large number of antennas to improve communication quality. As the number of antennas used for communication increases, the overhead and/or computational effort required for communication may increase. Techniques for improving efficiency in transmitting and receiving wireless signals using a large number of antennas may be needed in relatively high frequency bands.

As shown in fig. 4, communication system 400 may support MIMO-based communication. Communication system 400 may include one or more communication nodes that transmit and/or receive wireless signals. Each of the one or more communication nodes included in communication system 400 may include one or more antennas capable of transmitting and/or receiving wireless signals based on MIMO. Hereinafter, when describing a second exemplary embodiment of an antenna configuration in a communication system with reference to fig. 4, a description redundant to the description with reference to fig. 1 to 3 may be omitted.

The communication system 400 may support communication in an ultra-high frequency band (e.g., terahertz wave band). In an ultra-high frequency band such as a terahertz wave band, it may be necessary to utilize a very large number of antennas to improve communication quality. On the other hand, in an ultra-high frequency band such as a terahertz wave band, a line-of-sight (LoS) component may dominate a received wireless signal, and a Non-LoS (NLoS) component may be hardly present in the received wireless signal. The communication system 400 may include one or more antennas configured to easily support communication in an ultra-high frequency band (e.g., terahertz-wave band).

The communication system 400 may comprise a first communication node. The first communication node may comprise a first antenna 410. The first antenna 410 may support MIMO. The first antenna 410 may be composed of a plurality of antenna elements. The plurality of antenna elements constituting the first antenna 410 may be regularly or irregularly arranged. In an exemplary embodiment of the communication system 400, the first antenna 410 may have a structure in which a plurality of antenna elements are arranged at predetermined intervals.

In an antenna structure (e.g., ULA structure or UPA structure) in which a plurality of antenna elements are arranged at regular intervals, communication quality may be affected by a relationship between a spacing between the antenna elements and a wavelength of a wireless signal. In an antenna structure in which a plurality of antenna elements are arranged at regular intervals, an appropriate distance between the antenna elements may be differently determined according to a frequency, a reference frequency, or a carrier offset of a transmitted and received wireless signal.

In an ultra-high frequency band such as a terahertz wave band, a range of frequencies used may be relatively wide. For example, the terahertz-wave band may be defined as a 0.1THz to 10THz band. In other words, even in the terahertz wave band, the range of frequencies used may vary up to 100 times. Expressed differently, the range of wavelengths of wireless signals used may vary up to 100 times even in the terahertz wave band. That is, in an ultra-high frequency band such as a terahertz wave band, unless the spacing between antenna elements constituting the antenna structure is changed, it may not be easy to respond to a change in allocated or used frequency resources.

In an exemplary embodiment of the communication system 400, the first antenna 410 may have a "lens MIMO" structure. The first antenna 410 may have a structure in which a plurality of antenna elements are arranged at regular intervals (hereinafter, "antenna element pitch"). The first antenna 410 may further include one or more lenses capable of refracting the radiated wireless signal and/or the incident wireless signal. The lens included in the first antenna 410 may be an optical lens capable of physically refracting light. Each of the lenses included in the first antenna 410 may be an electromagnetic wave lens capable of refracting electromagnetic waves (EM waves) through interaction with an electromagnetic field or an electric field.

In the first antenna 410 including one or more lenses, the received wireless signal may be refracted by at least one of the one or more lenses to be incident. Accordingly, in the first antenna 410, the frequency of the wireless signal incident on each antenna element may be adjusted to match the antenna element spacing of the first antenna 410. Alternatively, in the first antenna 410 comprising one or more lenses, the transmitted wireless signal may be radiated in a refractive manner by at least one of the one or more lenses. Accordingly, in the first antenna 410, the frequency of the wireless signal radiated from each antenna element may be radiated in a manner adjusted to match the antenna element spacing of the first antenna 410. Since the lens (or the size of the lens) is variably applied to the antenna of the lens MIMO scheme according to a change in frequency band, the communication node can receive or transmit wireless signals in a manner suitable for the frequency band without changing the physical position or arrangement of antenna elements.

In an exemplary embodiment of the communication system 400, a first wireless signal received from the user #1 421 via the first receive beam 411-1 may be incident on the antenna element of the first antenna 410 by being refracted by the first lens. The second wireless signal received from user #2 422 through the second receive beam 411-2 may be incident on the antenna element of the first antenna 410 by being refracted by the second lens.

In the first antenna 410, a lens for refracting the received signal may be adaptively used for the frequency of the received signal, the reference frequency, and/or the antenna element spacing. In the first antenna 410, a lens for refracting the transmit signal may be adaptively used for the frequency of the transmit signal, the reference frequency, and/or the antenna element spacing. For example, in an exemplary embodiment of communication system 400, the same or similar mapping relationship as table 1 may be established.

TABLE 1

Referring to table 1, the frequency of the wireless signal received by the first antenna 410 in the communication system 400 may be set based on one or more preset reference frequencies. For example, in communication system 400, four reference frequencies may be set for wireless signal transmission and reception between one or more communication nodes. The four reference frequencies may correspond to F _REF#1(A THz)、F_REF#2(B THz)、F_REF #3 (C THz) and F _REF #4 (D THz).

The identifier of the lens may be represented as shown in table 1, or may be represented as a decimal value (i.e., 0, 1,2, 3) or a 2-bit binary value (i.e., 00, 01, 10, 11). The frequency value and the unit of the divided frequency band may be THz. In table 1, a relationship of "a < B < C < D" can be established. However, this is merely an example for convenience of description and exemplary embodiments of the communication system are not limited thereto.

The four reference frequencies (i.e., F _REF #1 to F _REF #4) may be references to frequencies of wireless signals for transmission and reception between one or more communication nodes. The frequency of each of the wireless signals transmitted and received between one or more communication nodes may be set based on one of four reference frequencies (i.e., F _REF #1 to F _REF #4) (hereinafter, F _REF #n) and a predetermined frequency difference F _Diff.

In an exemplary embodiment of communication system 400, each of the four reference frequencies (i.e., F _REF #1 to F _REF #4) may correspond to a minimum (or lowest) frequency of wireless signals transmitted and received between one or more communication nodes. In this case, each of the wireless signals transmitted and received between one or more communication nodes may be configured to have frequencies of F _REF #n to (F _REF#n+F_Diff).

In an exemplary embodiment of communication system 400, each of the four reference frequencies (i.e., F _REF #1 to F _REF #4) may correspond to a maximum (or highest) frequency of wireless signals transmitted and received between one or more communication nodes. In this case, each of the wireless signals transmitted and received between one or more communication nodes may be configured to have frequencies of (F _REF#n-F_Diff) to F _REF #n.

In an exemplary embodiment of communication system 400, each of the four reference frequencies (i.e., F _REF #1 to F _REF #4) may correspond to a center frequency of wireless signals transmitted and received between one or more communication nodes. In this case, each of the wireless signals transmitted and received between one or more communication nodes may be configured to have frequencies of (F _REF#n-F_Diff) to (F _REF#n+F_Diff).

The communication node may transmit or receive the wireless signal using a lens corresponding to a reference frequency corresponding to the transmitted or received wireless signal. For example, when receiving a wireless signal corresponding to F _REF #n, a first communication node including the first antenna 410 may receive the wireless signal using the lens #n in the first antenna 410. On the other hand, when transmitting a wireless signal corresponding to F _REF #n, the first communication node including the first antenna 410 may transmit the wireless signal using the lens #n in the first antenna 410.

On the other hand, the frequency of each wireless signal transmitted and received between one or more communication nodes may be set within a frequency band corresponding to one of four reference frequencies (i.e., F _REF #1 to F _REF #4). For example, in an exemplary embodiment of communication system 400, the same or similar mapping relationship as table 2 may be established.

TABLE 2

Reference frequency	Frequency (THz)	Reference frequency band (THz)	Reference lens
				F_REF#1	A	A1～A2	Lens #1
F_REF#2	B	B1～B2	Lens #2
				F_REF#3	C	C1～C2	Lens #3
F_REF#4	D	D1～D2	Lens #4

The communication node may transmit or receive the wireless signal using a lens corresponding to a frequency band of the transmitted or received wireless signal. For example, when the first communication node including the first antenna 410 receives a wireless signal having a frequency within a frequency band (N1 THz to N2 THz frequency band) corresponding to the reference frequency F _REF #n, the first communication node may receive the wireless signal by using the lens #n in the first antenna 410. On the other hand, when the first communication node including the first antenna 410 transmits a wireless signal having a frequency within the frequency band (N1 THz to N2 THz) corresponding to the reference frequency F _REF #n, the first communication node may transmit the wireless signal by using the lens #n in the first antenna 410.

At least some of the information (e.g., reference frequency information, reference lens information, etc.) included in table 1 or table 2 may be transmitted through system information (e.g., system information block (systeminformation block, SIB), master information block (master information block, MIB), etc.), RRC message (e.g., RRCReconfiguration, etc.), etc. For example, at least some information (e.g., reference frequency information, reference lens information, etc.) included in table 1 or table 2 may be transmitted to the terminal by the base station through system information or RRC message, etc.

The first communication node may receive at least some information (e.g., reference frequency information, reference lens information, etc.) included in table 1 or table 2 or a mapping relationship thereof from another communication node. For example, when the first communication node is a terminal, the first communication node may identify at least some information included in table 1 or table 2 and their mapping relationship based on the indication information received from the base station. On the other hand, the first communication node may configure itself at least some of the information included in table 1 or table 2 and their mapping relations. For example, when the first communication node is a base station or a terminal, the first communication node may determine a plurality of lenses (or reference lens information indicating a plurality of lenses) suitable for receiving wireless signals at a corresponding plurality of reference frequencies based on information about wavelengths corresponding to each of the plurality of reference frequencies and a spacing between antenna elements constituting the first antenna 410.

In determining the reference lens information, the size of the lens may be determined based on the number of antenna elements or the spacing between antenna elements in the antenna having the lens MIMO structure. For example, the total number of antennas M (or the maximum of the number of antennas M) that make up the first antenna 410 may be expressed asHere, L may correspond to a size (e.g., diameter, radius, circumference, etc.) of the lens, and λ may correspond to a wavelength of the wireless signal. Since the size of the lens may be inversely proportional to the wavelength, when a larger reference frequency (or frequency band having a larger reference frequency value) is used, the first communication node may apply a smaller sized lens, thereby enabling communication while maintaining the existing antenna array. For example, in table 1, when a < B < C < D, it can be seen that, among the reference lenses corresponding to the respective frequencies, lens #1 has the largest size and lens #4 has the smallest size. However, this is merely an example for convenience of description, and in the second exemplary embodiment of the antenna configuration in the communication system, the lens may be determined by adjusting various factors (e.g., size, refractive index, etc.) for determining the lens according to a change in frequency band.

In fig. 4, the antenna elements of the first antenna 410 using the three-dimensional lens are shown as being arranged along a three-dimensional hemisphere, but this is merely an example for convenience of description, and the second exemplary embodiment of the antenna configuration in the communication system is not limited thereto. For example, in an exemplary embodiment of communication system 400, two-dimensional or three-dimensional lenses may be used in a lens MIMO antenna. In a lens MIMO antenna, the antenna elements may be arranged in a two-dimensional or three-dimensional structure. In a lens MIMO antenna, the antenna elements may be arranged on a plane, arc or sphere.

In an exemplary embodiment of the communication system 400, antenna elements arranged in a two-dimensional structure in a lens MIMO antenna may be considered to correspond to the ULA structure described with reference to fig. 3. Antenna elements arranged in a three-dimensional structure in a lens MIMO antenna may be considered to correspond to the UPA structure described with reference to fig. 3.

As shown in fig. 5a and 5b, the communication system may support MIMO-based communication. A communication system may include one or more communication nodes that transmit and/or receive wireless signals. Each of one or more communication nodes included in the communication system may include one or more antennas capable of transmitting and/or receiving wireless signals based on MIMO. Each of the one or more communication nodes included in the communication system may include one or more antennas identical or similar to the first antenna 410 described with reference to fig. 4. Hereinafter, in describing an exemplary embodiment of a communication method based on the second exemplary embodiment of an antenna structure in a communication system with reference to fig. 5a and 5b, a description redundant to the description with reference to fig. 1 to 4 may be omitted.

As shown in fig. 5a, the first communication node may comprise a first antenna for receiving and/or transmitting wireless signals. The first antenna may be the same as or similar to the first antenna 410 described with reference to fig. 4. The first antenna may be configured to have a lens MIMO structure. The first antenna may include one or more lenses that refract the transmitted or received wireless signals.

The antenna response detected or measured by the plurality of antenna elements constituting the first antenna may have the same or similar pattern as the sinc function. The sinc function may be defined the same as or similar to equation 1.

[ Equation 1]

In equation 1, k may be a real number, e.g., 1 or pi. An antenna closer to the position corresponding to the main lobe (i.e., median) of the sinc function may have a larger antenna response, and an antenna farther from the position corresponding to the main lobe may have a smaller antenna response. The position of the main lobe of the sinc function relative to the antenna response can be determined from the AoA of the received signal. The receiving node may estimate the AoA of the received signal by identifying the antenna element (or index thereof) corresponding to the position of the main lobe, as shown in fig. 5 a. For example, the first communication node may estimate the AoA of the received signal by sequentially activating a plurality of antenna elements constituting the first antenna and identifying a position corresponding to a main lobe of the sinc function.

AoA (Φ _m、φ_n, etc.) can be estimated based on the angle (θm, θn, etc.) between each receive antenna element (m, n, etc.) and the center line (an imaginary line between the center of the first antenna and point B ₀). Alternatively, the AoA for each antenna element estimated in the above manner may be denoted as θ _m and θ _n.

In the exemplary embodiment shown in fig. 5a, the size (diameter, length, etc.) of the EM lens may correspond to D _y. The distance between the center of the lens and its lower end may correspond to D _y/2 and the distance between the center of the lens and its upper end may correspond to D _y/2. The spacing between the antenna elements can be set uniformly. Alternatively, the spacing between the antenna elements may be set based on the angle (θ _m、θ_n, etc.) between each receiving antenna element (m, n, etc.) and the center line. For example, the spacing between the antenna elements may be set to be proportional to the sine value (sin θ _m、sinθ_n, etc.) of the angle (θ _m、θ_n, etc.) between each receiving antenna element (m, n, etc.) and the center line.

Fig. 5a shows an exemplary embodiment of a first antenna comprising two-dimensionally arranged antenna elements and a two-dimensional lens. In this case, the first communication node may sequentially activate or deactivate each of the two-dimensionally arranged antenna elements, and recognize the reception result of the wireless signal incident through the two-dimensional lens. Thereby, the first communication node may estimate the AoA of the received signal. However, this is merely an example for convenience of description and exemplary embodiments of the communication system are not limited thereto. For example, the first antenna may be configured to include three-dimensionally arranged antenna elements and a three-dimensional lens. In this case, the first communication node may sequentially activate or deactivate each of the three-dimensionally arranged antenna elements, and recognize the reception result of the wireless signal incident through the three-dimensional lens. Thereby, the first communication node may estimate the AoA of the received signal.

The communication system can support a lens MIMO antenna taking into consideration broadband characteristics of an ultra-high frequency band such as a terahertz wave band. Exemplary embodiments of the communication system may support a scheme of variably setting a lens size according to a variation of an ultra-high frequency band such as a terahertz wave band.

Exemplary embodiments of the communication system may utilize a lens MIMO antenna composed of multiple antenna elements and support a two-step AoA estimation scheme to reduce the amount of computation or complexity required to estimate the AoA and channel of a received signal. The two-step AoA estimation scheme may include: a first step of dividing antenna elements into a plurality of antenna groups and deriving candidate antenna groups by comparing an estimated reception intensity of each antenna group with a predetermined threshold; second, it estimates the number of receive paths and AoA for each path by accurate sensing.

Although a scheme of estimating the AoA of a signal received in a lens MIMO antenna has been described with reference to fig. 5a, exemplary embodiments of the communication system are not limited thereto. For example, in an exemplary embodiment of the communication system, the communication node transmitting the wireless signal may determine the direction of the wireless signal based on the second exemplary embodiment of the antenna configuration.

As shown in fig. 5b, the first communication node transmitting the wireless signal may determine the transmission direction or AOD of the wireless signal by selecting a specific antenna element (or antenna) for transmitting the wireless signal from the first antennas having the same or similar structure as described with reference to fig. 5 a. In other words, the first communication node may select a specific antenna element (or antenna) in the first antenna to be utilized (or activated) in transmitting the wireless signal based on a transmission direction or AoD in which the wireless signal is desired to be transmitted.

Specifically, based on the angle (θ _m、θ_n, etc.) between each transmit antenna element (m, n, etc.) and the center line (e.g., an imaginary line between the center of the first antenna and point B ₀), the AOD (e.g., Φ _m、φ_n, etc.) at each transmit antenna element can be estimated. Alternatively, the AODs for the individual antenna elements as estimated may be denoted as phi _m and phi _n.

Fig. 5b shows an exemplary embodiment of a first antenna comprising two-dimensionally arranged antenna elements and a two-dimensional lens. In this case, the first communication node may transmit a wireless signal through the two-dimensional lens while sequentially activating or deactivating each of the two-dimensionally arranged antenna elements. The first communication node may receive feedback for wireless signals transmitted with the antenna elements activated at a particular time, thereby identifying a direction in which wireless signals transmitted by the respective antenna elements are transmitted from the first antenna, a transmission result of wireless signals transmitted by the respective antenna elements, a reception result of wireless signals transmitted by the respective antenna elements at the receiving node, and the like. Thus, the first communication node can identify or estimate the transmission direction with each antenna element. Alternatively, the first communication node may identify or estimate the direction and/or location of the receiving node receiving the wireless signal transmitted by the antenna element by receiving feedback on the wireless signal transmitted with the corresponding antenna element activated at a particular time. However, this is merely an example for convenience of description and exemplary embodiments of the communication system are not limited thereto. For example, the first antenna may be configured to include three-dimensionally arranged antenna elements and a three-dimensional lens. In this case, the first communication node can recognize the reception result of the wireless signal radiated through the three-dimensional lens by sequentially activating or deactivating each of the three-dimensionally arranged antenna elements. Thus, the first communication node may estimate, identify or determine the direction of transmission of the transmitted signal or the direction of the receiving node.

In the communication system, if the transmitting node transmits a wireless signal using the antenna described with reference to fig. 5b and the receiving node receives a wireless signal using the antenna described with reference to fig. 5a, both the transmitting node and the receiving node in the communication system can effectively estimate, identify or determine direction information, such as AoD, aoA, etc., of the wireless signal based on the second exemplary embodiment of the antenna configuration in the communication system.

As shown in fig. 6, communication system 600 may support MIMO-based communication. A communication system may include one or more communication nodes that transmit and/or receive wireless signals. Each of one or more communication nodes included in the communication system may include one or more antennas capable of transmitting and/or receiving wireless signals based on a lens MIMO scheme. Each of the one or more communication nodes included in the communication system may include one or more antennas identical or similar to the first antenna 410 described with reference to fig. 4. According to the first exemplary embodiment of the signal transmission and reception method in the communication system, the operation for selecting a lens may be performed in a lens MIMO scheme. Hereinafter, in describing a first exemplary embodiment of a signal transmission and reception method in a communication system with reference to fig. 6, a description redundant from the description with reference to fig. 1 to 5a may be omitted.

In an exemplary embodiment of the communication system 600, the first communication node 601 may correspond to a receiving node and the second communication node 602 may correspond to a transmitting node. The second communication node 602 may transmit data to the first communication node 601 through a first signal in an ultra-high frequency band (e.g., terahertz wave band). The first communication node 601 may receive a signal transmitted from the second communication node 602 in an ultra-high frequency band such as a terahertz wave band using one or more lens MIMO-based antennas. The second communication node 602 may send the first indication or the first indication information to the first communication node 601 before sending the first signal to the first communication node 601.

On the other hand, in another exemplary embodiment of the communication system 600, the second communication node 602 may correspond to a base station and the first communication node 601 may correspond to a terminal. The first communication node 601 may receive signals transmitted by the second communication node 602 or other communication nodes in an ultra-high frequency band such as a terahertz wave band using one or more lens MIMO-based antennas. The second communication node 602 may send a first indication or first indication information to the first communication node 601.

According to a first exemplary embodiment of a signal transmission and reception method in a communication system, the second communication node 602 may generate a first indication (S610). Here, the first indication may include information for receiving wireless signals using one or more lens MIMO based antennas. The first indication may include information about a reference frequency, a frequency band, a corresponding lens, etc. of the wireless signal transmitted from the second communication node 602. For example, the first indication may include at least some of the information shown in table 1 or table 2.

The second communication node 602 may send a first indication to the first communication node 601 (S620). The first indication may be transmitted to the first communication node 601 in a manner that is included in system information (e.g., SIB, MIB, etc.) or RRC message (e.g., RRCReconfiguration, etc.) transmitted from the second communication node 602.

The first communication node 601 may receive a first indication transmitted from the second communication node 602 (S620). The first communication node 601 may identify information included in the first indication. For example, the first communication node 601 may identify information about a reference frequency, a frequency band, a corresponding lens, etc. of the wireless signal transmitted from the second communication node 602 based on the first indication.

The second communication node 602 may generate a first signal for transmission to the first communication node 601 (S640). The second communication node 602 may transmit the generated first signal to the first communication node 601 (S650). Here, the first signal may be transmitted based on the reference frequency and/or frequency band indicated by the first indication. The first communication node 601 may receive a first signal (S660). Here, the first communication node 601 may receive the first signal using a lens corresponding to a frequency of the first signal.

On the other hand, if there is a change in the mapping relation for the lens transmitted by the first indication, the second communication node 602 may notify the first communication node 601 of this by an additional signal (e.g., a second indication). Alternatively, the first communication node 601 may send information about the lens the first communication node 601 uses for reception to the second communication node 602. The first communication node 601 and/or the second communication node 602 may set an index or indicator for each lens in the same or similar manner as shown in table 3.

TABLE 3

Reference lens	Lens index
		Lens #1	0(00)
Lens #2	1(01)
		Lens #3	2(10)
Lens #4	3(11)

The index of the lens may be expressed as a decimal value (i.e., 0, 1, 2, 3) or a 2-bit value (i.e., 00, 01, 10, 11), as shown in table 3. In an exemplary embodiment of the communication system 600, when a frequency band (reference frequency) for communication is changed to a new frequency band, it may be necessary to change a lens (or a reference lens group) according to the changed frequency band (i.e., the newly allocated frequency band). When the first communication node 601 is able to utilize a total of four lenses, the second communication node 602 may determine a lens suitable for the current situation of the first communication node 601 from among candidate lenses of the first communication node 601 based on the newly allocated frequency band, and transmit a signal indicating that the first communication node 601 selects a corresponding lens. Information about the index or indicator for each lens as shown in table 3 may be transmitted through system information or RRC message. When the number of lenses available by the first communication node 601 is k, information about the index for each lens may be transmitted in a manner allocated at least log ₂ k bits. For example, when the number of available lenses is 4 as shown in table 3, information about the index for each lens may be transmitted in a manner allocated at least 2 bits. On the other hand, when the number of available lenses is 1, information on the index for each lens may be transmitted in a manner allocated with at least 1 bit.

The situation shown in fig. 6 may correspond to a downlink transmission situation in which a second communication node 602 corresponding to a base station transmits signaling such as a first indication and a radio signal to one or more terminals including a first communication node 601. However, this is merely an example for convenience of description, and the first exemplary embodiment of the signal transmission and reception method in the communication system is not limited thereto. For example, the first exemplary embodiment of the signal transmission and reception method in the communication system can be applied to an uplink transmission case in which the second communication node 602 is a terminal and the first communication node 601 is a base station. Alternatively, the first exemplary embodiment of the signal transmission and reception method in the communication system may not be limited to a specific transmission mode such as uplink transmission, downlink transmission, and side link transmission, and may be applied to a case where at least one of the transmitting node and the receiving node includes a lens MIMO antenna. On the other hand, the first exemplary embodiment of the signal transmission and reception method in the communication system may be implemented in the following scheme: wherein the first communication node 601 transmits signaling (e.g., a first indication) including information about a reference frequency to the second communication node 602 and receives a wireless signal transmitted from the second communication node 602 with one of the reference frequencies through a lens MIMO antenna.

As shown in fig. 7, the communication system may be the same as or similar to communication system 600 described with reference to fig. 6. One or more communication nodes included in the communication system may include one or more antennas that are the same as or similar to the first antenna 410 described with reference to fig. 4. According to the second exemplary embodiment of the signal transmission and reception method in the communication system, an operation for estimating (or determining) a transmission direction in the lens MIMO scheme may be performed. Hereinafter, when describing a second exemplary embodiment of a signal transmission and reception method in a communication system with reference to fig. 7, a description redundant with the descriptions with reference to fig. 1 to 6 may be omitted.

In an exemplary embodiment of the communication system, the first communication node may correspond to a receiving node and the second communication node may correspond to a transmitting node. The second communication node may estimate a transmission direction to the first communication node by transmitting a second signal to the first communication node. The second communication node may determine a transmission candidate antenna group corresponding to the estimated transmission direction to the first communication node. Here, the second signal may correspond to a signal for estimating a transmission direction to the first communication node at the second communication node. The second signal may be a signal in an ultra-high frequency band (e.g., terahertz waves).

Specifically, the second communication node may transmit a second signal to the first communication node (S710). The second communication node may transmit the second signal to the first communication node while sequentially activating at least some of the one or more antenna elements constituting the first antenna included in the second communication node.

The second communication node may receive a response to the second signal (hereinafter, second response) from the first communication node (S715). The second communication node may perform estimation of the transmission direction of the first communication node based on the second response received from the first communication node at step S715 (S720).

In an exemplary embodiment of the communication system, the second response may comprise information about the result of receiving the second signal at the first communication node. Alternatively, the second response may comprise information obtained by the first communication node as a function of the result of receiving the second signal. For example, the second response may include information about the second signal, such as a reception angle, a reception direction, a reception strength, and channel information between the first communication node and the second communication node. Alternatively, the second response may comprise information about the location of the first communication node. Here, the information about the location of the first communication node may include information about an absolute location of the first communication node. Alternatively, the information about the location of the first communication node may comprise information about the relative location of the first communication node with respect to the second communication node. In this case, the second communication node may determine the transmission direction to the first communication node based on the information included in the second response.

On the other hand, in another exemplary embodiment of the communication system, the second communication node may not transmit a separate wireless signal to the first communication node, and may estimate or identify a transmission direction to the first communication node based on the wireless signal transmitted and received from the first communication node. For example, the second communication node may receive a signal transmitted from the first communication node by using the first antenna or the second antenna (which is a receiving antenna having the same or similar structure as the first antenna). The second communication node may estimate the direction of the first communication node based on the angle at which the first antenna (or the second antenna) receives the signal transmitted from the first communication node. Based on the direction of the first communication node estimated as described above, the second communication node may estimate the transmission direction to the first communication node.

The second communication node may determine a transmission candidate antenna group based on the estimated transmission direction to the first communication node (S730). For example, the transmission candidate antenna group determined at step S730 may include one or more antenna elements corresponding to the estimated direction of the first communication node. The transmission candidate antenna group determined at step S730 may include antenna elements adjacent to one or more antenna elements corresponding to the estimated direction of the first communication node. For example, in step S730, the transmission candidate antenna group may be determined as same as or similar to table 4.

TABLE 4

Observers	Direction of observation target (first communication node)	Transmitting candidate antenna group
			Second communication node	φ_2,i	A₂#(i-1)、A₂#i、A₂#(i+1)

Referring to table 4, the direction of the first communication node estimated at the second communication node may be represented as phi _2,i (or theta _2.i, etc.). Here, i may be an index corresponding to each of a plurality of directions in which the second communication node may transmit a wireless signal using the first antenna. Alternatively, i may be an index of each antenna element corresponding to each transmission direction in the first antenna corresponding to the second communication node. The second communication node may configure the transmission candidate antenna group to include the antenna element a ₂ # i corresponding to the estimated direction phi _2,i. The second communication node may configure the transmission candidate antenna group to include antenna elements a ₂ # (i-1) and a ₂ # (i+1) adjacent to the antenna element a ₂ # i corresponding to the estimated direction of the first communication node. The number of antenna elements included in the transmission candidate antenna group may be n ₂. Here, n ₂ may correspond to the number of antenna elements available simultaneously (i.e., the number of transmit antenna elements available) in the first antenna of the second communication node. Table 4 shows an exemplary embodiment with n ₂ being 3. However, this is merely an example for convenience of description, and the second exemplary embodiment of the signal transmission and reception method in the communication system is not limited thereto. When n ₂ is 5, for example, the transmission candidate antenna group may include antenna element a ₂ # i corresponding to the estimated direction of the first communication node, and may further include four antenna elements relatively close to antenna element a ₂ # i (e.g., a ₂#(i-2)、A₂#(i-1)、A₂#(i+1)、A₂ # (i+2)).

As shown in fig. 8, the communication system may be the same as or similar to communication system 600 described with reference to fig. 6. One or more communication nodes included in the communication system may include one or more antennas that are the same as or similar to the first antenna 410 described with reference to fig. 4. According to the third exemplary embodiment of the signal transmission and reception method in the communication system, an operation for estimating (or determining) a transmission direction in the lens MIMO scheme may be performed. Hereinafter, when describing a third exemplary embodiment of a signal transmission and reception method in a communication system with reference to fig. 8, a description redundant with the descriptions with reference to fig. 1 to 7 may be omitted.

In an exemplary embodiment of the communication system, the first communication node may correspond to a receiving node and the second communication node may correspond to a transmitting node. The first communication node may estimate a direction of reception of the wireless signal from the second communication node by receiving the third signal from the second communication node. The first communication node may determine a set of reception candidate antennas corresponding to the estimated reception direction. Here, the third signal may correspond to a signal used by the first communication node to estimate a reception direction of the wireless signal from the second communication node. The third signal may be a signal in an ultra-high frequency band (e.g., terahertz wave).

Specifically, the first communication node may receive a third signal from the second communication node (S810). The first communication node may receive the third signal while sequentially activating at least some of the one or more antenna elements constituting the first antenna included in the first communication node. Here, the third signal may be the same as or different from the second signal described with reference to fig. 7. The first communication node may perform estimation of a reception direction of the wireless signal from the second communication node based on the third signal received from the second communication node at step S810 (S820). In other words, the first communication node may perform an estimation of the direction of the second communication node.

In an exemplary embodiment of the communication system, the third signal may comprise information about the position or orientation of the second communication node. Alternatively, the third signal may include information on a result of receiving the signal transmitted from the first communication node at the second communication node, or may include information obtained based on the reception result. For example, the third signal may include information for signals received by the second communication node from the first communication node, such as a reception angle, a reception direction, a reception strength, and channel information between the first communication node and the second communication node. Alternatively, the third signal may comprise information about the location of the second communication node. In this case, the first communication node may estimate or identify the direction of the second communication node based on the information included in the third signal.

In another exemplary embodiment of the communication system, on the other hand, the first communication node may estimate the direction of the second communication node based on the angle at which the signal transmitted from the second communication node is received at the first antenna. Based on the direction of the second communication node estimated as described above, the first communication node may estimate the reception direction of the wireless signal from the second communication node.

The second communication node may determine a reception candidate antenna group based on the reception direction estimated at step S820 (S830). For example, the reception candidate antenna group determined at step S830 may include one or more antenna elements corresponding to the estimated direction of the second communication node. The reception candidate antenna group determined at step S830 may include antenna elements adjacent to one or more antenna elements corresponding to the estimated direction of the second communication node. For example, in step S830, the reception candidate antenna group may be determined as same as or similar to table 5.

TABLE 5

Referring to table 5, the direction of the second communication node estimated at the first communication node may be represented as phi _1,j (or theta _1,j, etc.). Here, j may be an index corresponding to each of a plurality of directions in which the first communication node may transmit wireless signals using the first antenna. Alternatively, j may be an index corresponding to each antenna element in the first antenna of the first communication node corresponding to each transmission direction. The first communication node may configure the reception candidate antenna group to include the antenna element a ₁ #j corresponding to the estimated direction phi _1,j. The first communication node may form the reception candidate antenna group to include antenna elements a ₁ # (j-1) and a ₁ # (j+1) adjacent to the antenna element a ₁ # j corresponding to the estimated direction of the second communication node. The number of antenna elements included in the reception candidate antenna group may be n ₁. Here, n ₁ may correspond to the number of antenna elements available simultaneously (i.e. the number of available receive antenna elements) in the first antenna of the first communication node. Table 5 shows an exemplary embodiment with n ₁ being 3. However, this is merely an example for convenience of description, and the third exemplary embodiment of the signal transmission and reception method in the communication system is not limited thereto. When n ₁ is 5, for example, the reception candidate antenna group may include antenna element a ₁ # j corresponding to the estimated direction of the second communication node, and may further include four antenna elements relatively close to antenna element a ₁ # j (e.g., A ₁#(j-2)、A₁#(j-1)、A₁#(j+1)、A₁ # (j+2)).

The first communication node may transmit information about the reception candidate antenna group determined in step S830 to the second communication node (S840). In step S840, information on the reception candidate antenna group may be transmitted through an RRC message or RRC signaling (e.g., an RRC connection reconfiguration complete message, a UE information response, and UE assistance information). Alternatively, separate signaling (e.g., RRC signaling) may be defined to transmit information about the reception candidate antenna group.

As shown in fig. 9, the communication system 900 may be the same or similar to the communication system 600 described with reference to fig. 6. One or more communication nodes included in communication system 900 may include one or more antennas that are the same or similar to first antenna 410 described with reference to fig. 4. According to a fourth exemplary embodiment of a signal transmission and reception method in a communication system, an operation for determining or selecting a combination of a transmission antenna element and a reception antenna element in a lens MIMO scheme may be performed. Hereinafter, when describing a fourth exemplary embodiment of a signal transmission and reception method in a communication system with reference to fig. 9, a description redundant with the descriptions with reference to fig. 1 to 8 may be omitted.

One-to-one transmit/receive antenna element combination determination scheme

In an exemplary embodiment of the communication system 900, the first communication node 901 may correspond to a receiving node and the second communication node 902 may correspond to a transmitting node. The second communication node 902 may estimate the transmission direction to the first communication node 901 using the same or similar method as described with reference to fig. 7, and may determine a transmission candidate antenna group corresponding to the estimated transmission direction. The first communication node 901 may estimate the reception direction of the signal from the second communication node 902 using the same or similar method as described with reference to fig. 8, and may determine a reception candidate antenna group corresponding to the estimated reception direction. The set of reception candidate antennas may comprise one or more reception candidate antenna elements. The first communication node 901 may transmit information on the determined reception candidate antenna group to the second communication node 902. The second communication node 902 may receive information about the reception candidate antenna group determined by the first communication node 901 from the first communication node 901. The set of reception candidate antennas may comprise one or more reception candidate antenna elements.

The second communication node 902 may determine one or more antenna element combinations (or antenna combinations) based on the information about the reception candidate antenna group determined by the first communication node 901 and the information about the transmission candidate antenna group determined by the second communication node 902. Here, each of the one or more antenna element combinations (or antenna combinations) may be configured as a combination of one or more transmission candidate antenna elements included in the transmission candidate antenna group determined by the second communication node 902 and one or more reception candidate antenna elements included in the reception candidate antenna group determined by the first communication node 901. For example, one or more antenna element combinations may be configured the same as or similar to table 6.

TABLE 6

Combined index (4 bit)	Transmitting antenna element (second communication node)	Receiving antenna element (first communication node)
			1(0000)	A₂#1、A₂#2	A₁#3
2(0001)	A₂#1、A₂#2	A₁#4
			3(0010)	A₂#1、A₂#2	A₁#5
…	…	…
			8(0111)	A₂#2、A₂#3	A₁#4
9(1000)	A₂#2、A₂#3	A₁#5

The second communication node 902 may transmit information regarding the one or more antenna element combinations determined at step 910 to the second communication node 901 (S915). The first communication node 901 may receive information about a combination of one or more antenna elements transmitted from the second communication node 902 (S915). The first communication node 901 may identify information about one or more antenna element combinations (which are represented in the same or similar manner as table 6) (S920).

The first communication node 901 and the second communication node 902 may perform a process for measuring reception strength by wireless signal transmission and reception using one or more antenna element combinations (S925). For example, the first communication node 901 and the second communication node 902 may perform a process of measuring Reference Signal Received Power (RSRP) for each of one or more antenna element combinations. For example, at step S925, the second communication node 902 may transmit a wireless signal (e.g., a reference signal) with a respective transmit antenna element of each combined index i (1, 2, … 9). The second communication node 902 may receive the reference signal for each combined index i with a corresponding receive antenna element. That is, at step S925, the result (e.g., RSRP) of receiving and measuring the wireless signal transmitted from the transmitting antenna element of the second communication node 902 at the receiving antenna element of the first communication node 901 may be measured for each combined index i. The first communication node 901 may transmit information on the measurement result obtained in step S925 to the second communication node 902. The information about the measurement result transmitted from the first communication node 901 to the second communication node 902 at step S930 may include at least some of the information shown in table 7.

TABLE 7

The second communication node 902 may receive information about the measurement result transmitted from the first communication node 901 (S930). The second communication node 902 may determine a priority of each antenna element combination based on the information about the measurement result received at step S930 (S935). That is, the second communication node 902 may determine the priority of each antenna element group based on the reception intensity measurement results for each antenna element combination received from the first communication node 901. For example, when information about the measurement results is given as in table 7, the priorities of the individual antenna element combinations may be determined in the same or similar manner as in table 8.

TABLE 8

Combined index (4 bit)	Priority level
		1(0000)	7
2(0001)	1 (Selected)
		3(0010)	9
…	…
		8(0111)	3
9(1000)	5

Referring to table 8, the second communication node 902 may determine the priority of each combination index based on the reception intensity value corresponding to each combination index in the measurement result representing (as shown in table 7). The second communication node 902 may select one or more indexes based on the determined priority. Table 8 shows an exemplary embodiment in which the second communication node 902 selects the combination index 2, but this is merely an example for convenience of description, and a fourth exemplary embodiment of the signal transmission and reception method is not limited thereto. In an exemplary embodiment of the communication system, the first communication node 901 and the second communication node 902 may perform mutual communication based on information on the reception strengths of the respective antenna element combinations measured at step S925 or the priorities determined at step S935.

The operations described with reference to tables 6 to 8 and fig. 9 are summarized in table 9.

TABLE 9

Table 9 shows a beam/antenna element selection procedure when the second communication node knows information about the antenna element combinations of the first communication node and the second communication node, information about their combination indexes, and the like. In an exemplary embodiment of the communication system, the second communication node (e.g., a base station) may transmit a reference signal to the first communication node (e.g., a terminal). The second communication node may provide the first communication node with information about the combined index, indicators related to measurement and reporting of the reception strength of the reference signal, etc. The second communication node may transmit information on the combination index, an indicator related to measurement of reception strength of the reference signal and response (or report), or the like, before or after transmitting the reference signal. Alternatively, the information may be transmitted together with the reference signal. The first communication node may measure the reception intensity for each antenna element combination based on the information and the reference signal transmitted from the second communication node, and transmit a response (or report) including information on the measured reception intensity to the second communication node. The second communication node may determine the priority of each antenna combination based on the response (or report) from the first communication node. The second communication node may transmit information about the determined priorities of the respective antenna combinations or information about one or more antenna combinations selected based on the determined priorities to the first communication node.

One-to-many transmit/receive antenna element combination determination scheme

The second communication node may perform the operations described with reference to fig. 9 with other communication nodes in addition to the first communication node. The second communication node may be referred to herein as a "transmitting node" and the other communication nodes including the first communication node may be referred to as "receiving nodes". In an exemplary embodiment of the communication system, the transmitting node may correspond to a base station and the receiving node may correspond to a terminal. In this case, the "one-to-many transmission/reception antenna element combination determination scheme" may be referred to as "an antenna element combination determination scheme between a base station and a terminal in a multi-terminal environment" or "a beamforming scheme between a base station and a terminal in a multi-terminal environment". However, this is merely an example for convenience of description, and the fourth exemplary embodiment of the signal transmission and reception method is not limited thereto.

When performing an operation for determining an antenna element combination with a plurality of receiving nodes, the transmitting node may comprehensively consider communication performance of the respective receiving nodes. For example, when there are two or more receiving nodes, a link between a transmitting node and one receiving node (e.g., a link between a transmitting beam and a receiving beam) may have an interfering effect on a link between the transmitting node and another receiving node. Thus, for interference management, it may be necessary to consider the antenna gains of multiple receiving nodes simultaneously to determine the antenna element combination.

In an exemplary embodiment of the communication system, each of the transmitting node and the plurality of receiving nodes may determine a lens to be applied to its antenna. This may be the same or similar to the configuration described with reference to fig. 6. Estimation of the transmission angle and the arrival angle may be performed between the transmitting node and each of the plurality of receiving nodes. This may be the same or similar to the configuration described with reference to fig. 7 and 8. The transmitting node may determine a transmission candidate antenna group for the receiving node. For example, a transmitting node may determine a transmission candidate antenna group for a plurality of receiving nodes. Alternatively, the transmitting node may determine a transmission candidate antenna group for each of the plurality of receiving nodes. For example, the transmitting node may determine a first transmit candidate antenna group for the first receiving node, a second transmit candidate antenna group for the second receiving node, and so on. Each receiving node may determine a set of reception candidate antennas based on its estimated angle of arrival (or reception direction) with respect to the transmitting node. Each receiving node may determine a set of reception candidate antennas based on its estimated angle of arrival (or reception direction) with respect to each transmitting node. All possible combinations of transmit antenna elements and receive antenna elements may be identified between a transmitting node and multiple receiving nodes. Each of the plurality of receiving nodes may perform a reception strength measurement for the received reference signal. Thus, the performance of all possible combinations of transmit and receive antenna elements can be measured.

Specifically, the transmission candidate antenna groups for the plurality of receiving nodes may be determined by the transmitting node, the same as or similar to table 10.

TABLE 10

Referring to table 10, a transmitting node may determine a transmission candidate antenna group based on a direction phi _Tx,2 of a receiving node a, a direction phi _Tx,3 of a receiving node B, a direction phi _Tx,10 of a receiving node C, and a number n ₂ of available transmitting antenna elements of the transmitting node.

N ₂ may be a reference for determining the number of transmission candidate antenna elements corresponding to the direction of each receiving node. For example, table 10 shows an exemplary embodiment of n ₂ =3. In this case, the transmission candidate antenna group may be configured as a set of three transmission candidate antenna elements { a _Tx#1、A_Tx#2、A_Tx #3} corresponding to the direction Φ _Tx,2 of the receiving node a, a set of three transmission candidate antenna elements { a _Tx#2、A_Tx#3、A_Tx #4} corresponding to the direction Φ _Tx,3 of the receiving node B, and a union { a _Tx#1、A_Tx#2、A_Tx#3、A_Tx#4、A_Tx#9、A_Tx#10、A_Tx #11} of a set of three corresponding transmission candidate antenna elements { a _Tx#9、A_Tx#10、A_Tx #11} corresponding to the direction Φ _Tx,10 of the receiving node C.

Alternatively, n ₂ may be a reference for determining the number of transmission candidate antenna elements included in the transmission candidate antenna group. For example, table 10 is considered to show an exemplary embodiment of n ₂ = 7. In this case, the transmission candidate antenna group may include 7 transmission candidate antenna elements { a _Tx#1、A_Tx#2、A_Tx#3、A_Tx#4、A_Tx#9、A_Tx#10、A_Tx #11} corresponding to the direction Φ _Tx,2 of the receiving node a, the direction Φ _Tx,3 of the receiving node B, and the direction Φ _Tx,10 of the receiving node C.

On the other hand, the reception candidate antenna group for the transmitting node may be determined by a plurality of receiving nodes, the same as or similar to table 11.

TABLE 11

Referring to table 11, the receiving node may determine one or more reception candidate antenna groups based on the directions phi _{Rx_A,4}、φ_{Rx_B,5} and phi _{Rx_C,6} of the transmitting node (or the AOA of the received signal transmitted from the transmitting node) and the number n _{1_A}、n_{1_B} and n _{1_C} of available antenna elements at the respective receiving nodes.

Here, each of n _{1_A}、n_{1_B} and n _{1_C} may be a reference for determining the number of reception candidate antenna elements corresponding to the direction of the transmitting node from the perspective of each receiving node. For example, case #1 of table 11 shows an exemplary embodiment of n _{1_A}＝1、n_{1_B} =1 and n _{1_C} =1. In this case, from the perspective of the respective receiving node, the reception candidate antenna group may include reception candidate antenna elements a _{Rx_A}#4、A_{Rx_B} #5 and a _{Rx_C} #2 corresponding to directions phi _{Rx_A,4}、φ_{Rx_B,5} and phi _{Rx_C,6} of the transmitting node. On the other hand, case #2 of table 11 shows exemplary embodiments of n _{1_A}＝1、n_{2_B} =2 and n _{1_C} =2. In this case, from the perspective of each receiving node, one or more of the reception candidate antenna groups may include a _{Rx_A} #4 corresponding to the direction phi _{Rx_A,4} of the transmitting node, A _{Rx_B} #4 and a _{Rx_B} #5 corresponding to a direction Φ _{Rx_B,5} of the transmitting node and a _{Rx_C} #2 and a _{Rx_C} #3 corresponding to a direction Φ _{Rx_C,6} of the transmitting node.

The transmitting node may obtain information about the reception candidate antenna group from the receiving node. The transmitting node may determine one or more antenna element combinations (or antenna combinations) based on the information about the transmission candidate antenna group and the information about the reception candidate antenna group. Here, each of the one or more antenna element combinations may be configured as a combination of one or more transmission candidate antenna elements included in the transmission candidate antenna group determined by the transmitting node and one or more reception candidate antenna elements included in the reception candidate antenna group determined by the receiving node. For example, information regarding one or more antenna element combinations may be configured to include at least some of the information shown in table 12.

TABLE 12

Referring to table 12, when determining a transmission candidate antenna group of a transmitting node and a reception candidate antenna group of a receiving node, the transmitting node may select antenna elements according to the number of available antennas for each of them to determine possible combinations of the transmitting antenna and the receiving antenna. Here, in order to determine the priority of each antenna combination, the transmitting node may consider a plurality of characteristics and conditions, such as mobility (or Doppler Shift (DS)) of each receiving node, delay requirement (LR) of each receiving node, network delay, and reception strength (e.g., RSRP) of a reference signal (e.g., SSB or CSI-RS). In table 12, DS _A、DS_B and DS _C may refer to the DS values of receiving node a, receiving node B, and receiving node C, respectively, and LR _A、LR_B and LR _C may refer to the LR of receiving node a, receiving node B, and receiving node C, respectively. The numbers listed in table 12 can be regarded as written under the assumption that the communication environments of all antenna elements existing in the respective receiving nodes are the same. However, this is merely an example for convenience of description, and the fourth exemplary embodiment of the signal transmission and reception method in the communication system is not limited thereto. For example, the fourth exemplary embodiment of the signal transmission and reception method in the communication system can be applied identically or similarly to the case when the communication environments between the transmission node and the reception node are different, when the communication environments between antennas within the reception node are different, or the like.

The transmitting node may determine the priority of each antenna combination based on information about each receiving node and each antenna combination. For example, the transmitting node may determine the priority of each antenna combination based on at least some of the RS, LR, or received strength of each respective antenna combination. Alternatively, the transmitting node may configure the priority by taking into consideration factors that determine the communication environment between the transmitting node and the receiving nodes (e.g., priority of data to be transmitted to the receiving nodes, total data rate for all receiving nodes, and minimum data rate for each receiving node).

Table 12 shows a priority determination process in the case where the number of available antennas of the transmitting node is 3 (for example, the case shown in table 7) and the number of available antennas of each receiving node is 1 (for example, the case shown in table 11). Thus, the transmitting node may determine the priority of the antenna combination as shown in table 13.

TABLE 13

Referring to table 13, the transmitting node may determine (or decide) the priority of the combination based on the combination of the transmitting antenna element and the receiving antenna element as configured in table 12. Based on the determined priorities, the transmitting node may ultimately determine transmit and receive beamforming (i.e., antenna elements to be utilized when transmitting signals at the transmitting node and receiving signals at each receiving node).

The operations described with reference to tables 9 to 13 are summarized as shown in table 14.

TABLE 14

Table 14 shows a beam/antenna element selection procedure when the transmitting node knows information about antenna element combinations of the transmitting node and the receiving node, information about combination indexes, and the like. In an exemplary embodiment of the communication system, a transmitting node (e.g., a base station) may transmit a reference signal to a receiving node (e.g., a terminal). The transmitting node may provide the receiving node with information about the combined index, indicators related to measurement and reporting of the reception strength of the reference signal, etc. The transmitting node may transmit information on the combination index, an indicator related to measurement and reporting of the reception strength of the reference signal, and the like before or after transmitting the reference signal. Alternatively, the information may be transmitted together with the reference signal. The receiving node may measure the reception intensity for each antenna element combination based on the information and the reference signal transmitted from the transmitting node, and transmit a response (or report) including information about the measured reception intensity to the transmitting node. The transmitting node may determine the priority of each antenna combination based on the response (or report) from the receiving node. The transmitting node may transmit information about the determined priorities of the respective antenna combinations or information about one or more antenna combinations selected based on the determined priorities to the receiving node.

As shown in fig. 10, the communication system may be the same as or similar to communication system 600 described with reference to fig. 6. One or more communication nodes included in the communication system may include one or more antennas that are the same as or similar to the first antenna 410 described with reference to fig. 4. According to a fifth exemplary embodiment of a signal transmission and reception method in a communication system, an operation for determining whether a combination of a transmission antenna element and a reception antenna element needs to be reselected in a lens MIMO scheme may be performed. Hereinafter, when describing a fifth exemplary embodiment of a signal transmission and reception method in a communication system with reference to fig. 10, a description redundant with the description with reference to fig. 1 to 9 may be omitted.

In an exemplary embodiment of the communication system, the first communication node may correspond to a receiving node and the second communication node may correspond to a transmitting node. The first communication node and the second communication node may determine the transmission candidate antenna group and the reception candidate antenna group by using the same or similar method as described with reference to fig. 7 and 8. The first communication node and the second communication node can determine combinations of transmission antenna elements and reception antenna elements (i.e., antenna element combinations) constituting the transmission candidate antenna group and the reception candidate antenna group by using the same or similar method as described with reference to fig. 9. The first communication node and the second communication node may determine the determined priority of the one or more antenna element combinations by utilizing the same or similar methods as described with reference to fig. 9. Here, the first communication node and the second communication node may determine whether one or more antenna element combinations configured as described above or priorities of one or more antenna element combinations need to be reselected.

Specifically, the first communication node may determine whether a reselection of the antenna element combination is required (S1010). The first communication node may identify a transmission and reception result for one or more currently selected antenna element combinations and compare the identified transmission and reception result to a first threshold. For example, the first communication node may measure a received strength (e.g., RSRP) for one or more currently selected antenna element combinations. If the measured received strength is greater than or equal to the first threshold, the first communication node may determine that a reselection of the corresponding antenna element combination is not required. On the other hand, if the measured reception strength is less than the first threshold, the first communication node may determine that a reselection of the corresponding antenna element combination is required.

The first communication node may transmit a reselection indicator based on the result of the determination of step S1010 (S1020). The first communication node may generate a reselection indicator indicating the result of the determination of step S1010. The reselection indicator may indicate whether a reselection procedure is required. In the reselection procedure, at least a part of the following operations may be performed again: the operations described with reference to fig. 7 (e.g., determination of a transmission candidate antenna group), the operations described with reference to fig. 8 (e.g., determination of a reception candidate antenna group), and the operations described with reference to fig. 9 (e.g., determination of an antenna element combination and its priority). When the reselection indicator indicates that a reselection procedure is required, the reselection procedure may be triggered when the first communication node sends the reselection indicator to the second communication node. On the other hand, when the reselection indicator does not indicate that a reselection procedure is required, wireless communication may be performed based on the currently selected one or more antenna element combinations. In an exemplary embodiment of the communication system, the reselection indicator may be configured the same as or similar to table 15.

TABLE 15

Table 15 is merely an example for convenience of description, and exemplary embodiments of the communication system are not limited thereto. For example, in another exemplary embodiment of the communication system, when the value of the re-sense indicator is 0, it may mean that a re-selection process is required, and when the value of the re-sense indicator is 1, it may mean that a re-selection process is not required.

The reselection indicator configured as shown in table 15 may be transmitted through uplink control information (uplink control information, UCI), downlink control information (downlink control information, DCI), or the like, and may be transmitted through RRC signaling such as a UE information response and UE assistance information. Alternatively, new RRC signaling may be defined for transmitting the reselection indicator.

As shown in fig. 11, the communication system may be the same as or similar to communication system 600 described with reference to fig. 6. One or more communication nodes included in the communication system may include one or more antennas that are the same as or similar to the first antenna 410 described with reference to fig. 4. According to the sixth exemplary embodiment of the signal transmission and reception method in the communication system, an operation for determining a transmission direction and a reception direction in the lens MIMO scheme may be performed. Hereinafter, when describing a sixth exemplary embodiment of a signal transmission and reception method in a communication system with reference to fig. 11, a description redundant with the description with reference to fig. 1 to 10 may be omitted.

In an exemplary embodiment of the communication system, the first communication node may perform an operation of determining a lens to be used for receiving a wireless signal at a first antenna configured in a lens MIMO scheme (S1110). In step S1110, the first communication node may perform at least some of the same or similar operations as those constituting the first exemplary embodiment of the signal transmission and reception method in the communication system described with reference to fig. 6. The first communication node may determine a lens to be used for each reference frequency or frequency band based on the first indication received from the second communication node.

In an exemplary embodiment of the communication system, the first communication node and the second communication node may perform an operation for determining a transmission candidate antenna group and a reception candidate antenna group (S1120). The second communication node may determine the transmission candidate antenna group by using the same or similar method as described with reference to fig. 7. The first communication node may determine the reception candidate antenna group by using the same or similar method as described with reference to fig. 8.

In an exemplary embodiment of the communication system, the first communication node and the second communication node may determine one or more antenna element combinations based on the transmission candidate antenna group and the reception candidate antenna group determined in step S1120, and may measure a reception strength (e.g., RSRP) for each of the determined one or more antenna element combinations (S1130). The first communication node and the second communication node may perform operations according to steps S910 to S925 described with reference to fig. 9.

In an exemplary embodiment of the communication system, the first communication node and the second communication node may determine priorities of the respective antenna element combinations based on the result of the measurement of step S1130 (S1140). Here, the first communication node and the second communication node may perform operations according to steps S930 to S935 described with reference to fig. 9. The operation of determining the priority may be performed based on a single condition or a plurality of conditions.

In an exemplary embodiment of the communication system, the first communication node and the second communication node may determine whether a reselection of the antenna element combination is required (S1150). The first communication node may determine whether a reselection of the antenna element combination is required by using the same or similar method as described with reference to fig. 10, and may transmit a reselection indicator indicating the result of the determination. When it is determined that the antenna element combination needs to be reselected as a result of the determination of step S1150, at least a part of the operations according to steps S1120 to S1140 may be performed again. On the other hand, when it is determined that the antenna element combination does not need to be reselected as a result of the determination of step S1150, the first communication node and the second communication node may perform mutual communication based on the currently selected antenna element combination. For example, the second communication node may transmit a beam in the direction of the second communication node based on one or more transmit antenna elements corresponding to the currently selected combination of antenna elements. The first communication node may receive a beam transmitted from the second communication node based on one or more receive antenna elements corresponding to the currently selected combination of antenna elements.

According to the method and apparatus for transmitting and receiving signals in a communication system, MIMO-based beam transmission and reception performance can be improved for transmitting and receiving wireless signals using a large number of antennas in a high frequency band. In a communication system, a transmitting node and a receiving node transmitting and receiving wireless signals using lens MIMO structured antennas may determine a transmission candidate antenna group and a reception candidate antenna group based on the results of mutual wireless signal transmission and reception. The transmitting node and the receiving node may determine one or more antenna element combinations based on the transmission candidate antenna group and the reception candidate antenna group, and may perform mutual wireless communication based on the determined antenna element combinations. Thus, the transmitting node and the receiving node can determine the optimal transmitting direction and receiving direction for mutual communication.

However, the effects that the exemplary embodiments of the signal transmission and reception method and apparatus may achieve in the communication system are not limited to those mentioned above. Based on the configuration described in the present invention, it is expected that other effects not mentioned can be clearly understood by those skilled in the art to which the present invention pertains.

The operations of the method according to the exemplary embodiment of the present invention may be embodied as a computer-readable program or code in a computer-readable recording medium. The computer readable recording medium may include all types of recording apparatuses storing data readable by a computer system. Furthermore, the computer-readable recording medium may store and execute a program or code, which may be distributed in computer systems connected through a network and read by a computer in a distributed manner.

The computer readable recording medium may include a hardware device such as a ROM, a RAM, or a flash memory that is specially configured to store and execute program instructions. The program instructions may include not only machine language code created by a compiler but also high-level language code that may be executed by a computer using an interpreter.

Although some aspects of the invention have been described in the context of apparatus, these aspects may indicate corresponding descriptions in terms of methods, and blocks or apparatus may correspond to steps or features of steps of the methods. Similarly, aspects described in the context of methods may be represented as features of respective blocks or items or respective devices. Some or all of the steps of the method may be performed by (or using) a hardware device, such as a microprocessor, a programmable computer, or electronic circuitry. In some embodiments, one or more of the most important steps of the method may be performed by such an apparatus.

In some example embodiments, programmable logic devices such as field programmable gate arrays may be used to perform some or all of the functions of the methods described herein. In some exemplary embodiments, a field programmable gate array may be operated with a microprocessor to perform one of the methods described herein. Generally, the method is preferably performed by specific hardware means.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.

Claims

1. A method of operation of a first communication node in a communication system, comprising:

determining a first lens to be applied to a first transmit antenna of a first communication node;

Identifying a first transmission direction to a second communication node of the communication system;

determining a transmission candidate antenna group among a plurality of transmission antenna elements constituting a first transmission antenna, the transmission candidate antenna group including one or more transmission antenna elements capable of transmitting a wireless signal in a first transmission direction through a first lens;

receiving information on a reception candidate antenna group from a second communication node;

Determining one or more antenna element combinations based on one or more transmit antenna elements included in the transmit candidate antenna group and one or more receive antenna elements included in the receive candidate antenna group; and

Wireless communication with the second communication node is performed based on the one or more antenna element combinations.

2. The operating method of claim 1, wherein one or more transmit antenna elements included in the transmit candidate antenna group are selected based on a first transmit antenna element corresponding to a first transmit angle determined from the first transmit direction and the first lens.

3. The method of operation of claim 1, wherein the first transmission direction is identified based on location information of a first communication node, and one or more receive antenna elements included in the receive candidate antenna group are selected based on a first receive antenna element determined based on a first reception direction of the first communication node identified at a second communication node and a first angle of incidence determined from a second lens of a first receive antenna applied to the second communication node.

4. The method of operation of claim 1, wherein each of the one or more antenna element combinations includes at least one transmit antenna element corresponding to a number of transmit antenna elements available at the same time as a first communication node included in the one or more transmit antenna elements in the transmit candidate antenna set and at least one receive antenna element corresponding to a number of receive antenna elements available at the same time as a second communication node included in the one or more receive antenna elements in the receive candidate antenna set.

5. The method of operation of claim 1, wherein performing wireless communication with a second communication node comprises: information about one or more antenna element combinations is transmitted to the second communication node, wherein the information about the one or more antenna element combinations indicates a combination index corresponding to each of the one or more antenna element combinations and a mapping relationship between at least one transmit antenna element and at least one receive antenna element.

6. The method of operation of claim 1, wherein performing wireless communication with a second communication node comprises:

transmitting information about one or more antenna element combinations to a second communication node;

performing a first measurement procedure with the second communication node based on the information about the one or more antenna element combinations;

identifying a received strength corresponding to each of the one or more antenna element combinations based on the first measurement procedure; and

A priority of each of the one or more antenna element combinations is determined based on a received strength corresponding to each of the one or more antenna element combinations.

7. The method of operation of claim 1, wherein performing wireless communication with a second communication node comprises: a reselection indicator is received from the second communication node, the reselection indicator indicating whether a reselection procedure for one or more combinations of antenna elements is required, wherein the reselection procedure is triggered when the reselection indicator indicates that a reselection procedure is required.

8. The method of operation of claim 1, wherein determining the first lens comprises:

identifying information about a first reference frequency for determining a lens to be applied to a first transmit antenna; and

The first lens is determined based on the information about the first reference frequency and the information about the first frequency for communicating with the second communication node.

9. The method of operation of claim 1, further comprising: prior to receiving information about the set of receive candidate antennas,

Transmitting a first indication comprising information about a second reference frequency to a second communication node for determining a lens to be applied to a first receive antenna of the second communication node; and

Transmitting first scheduling information, the first scheduling information comprising information about a first frequency for communicating with a second communication node,

Wherein the information about the second reference frequency and the information about the first frequency are used to determine a second lens to be applied to the first receiving antenna in the second communication node.

10. A method of operation of a first communication node in a communication system, comprising:

determining a first lens to be applied to a first receive antenna of a first communication node;

identifying a first direction of reception for a second communication node of the communication system;

determining a reception candidate antenna group among a plurality of reception antenna elements constituting a first reception antenna, the reception candidate antenna group including one or more reception antenna elements capable of receiving a wireless signal received at the first reception antenna in a first reception direction through a first lens;

transmitting information about the reception candidate antenna group to the second communication node;

Receiving information from the second communication node regarding one or more antenna element combinations determined based on one or more receive antenna elements included in the receive candidate antenna group and one or more transmit antenna elements included in the transmit candidate antenna group determined by the second communication node; and

11. The method of operation of claim 10, wherein one or more transmit antenna elements included in the transmit candidate antenna set are selected based on a first transmit antenna element corresponding to a first transmit angle determined based on a first transmit direction to the first communication node identified at the second communication node and a second lens of the first transmit antenna to be applied to the first communication node.

12. The method of operation of claim 10, wherein one or more receive antenna elements included in the receive candidate antenna group are selected based on a first receive antenna element corresponding to a first angle of incidence determined from the first receive direction and the first lens.

13. The method of operation of claim 10, wherein each of the one or more antenna element combinations includes at least one transmit antenna element corresponding to a number of transmit antenna elements available at the same time as a second communication node included in the one or more transmit antenna elements in the transmit candidate antenna set and at least one receive antenna element corresponding to a number of receive antenna elements available at the same time as a first communication node included in the one or more receive antenna elements in the receive candidate antenna set.

14. The method of operation of claim 10, wherein performing wireless communication with a second communication node comprises:

Information about a reception intensity corresponding to each of the one or more antenna element combinations is transmitted to the second communication node.

15. The method of operation of claim 10, wherein performing wireless communication with a second communication node comprises: a reselection indicator is sent to the second communication node, the reselection indicator indicating whether a reselection procedure for one or more combinations of antenna elements is required, wherein the reselection procedure is triggered when the reselection indicator indicates that a reselection procedure is required.

16. The method of operation of claim 15, wherein transmitting a reselection indicator comprises:

identifying a reception intensity corresponding to each of the one or more antenna element combinations;

Performing a determination of whether a reselection procedure is required based on the received strength corresponding to each of the one or more antenna element combinations;

generating a reselection indicator based on a result of the determination of whether the reselection process is required; and

The generated reselection indicator is sent to the second communication node.

17. A transmitting node in a communication system, comprising a processor, wherein the processor causes the transmitting node to perform:

determining a first lens to be applied to a first transmit antenna of a transmit node;

Identifying a transmission direction to a plurality of receiving nodes of the communication system, respectively;

Determining a transmission candidate antenna group among a plurality of transmission antenna elements constituting a first transmission antenna, the transmission candidate antenna group including one or more transmission antenna elements capable of transmitting a wireless signal in a transmission direction through a first lens;

receiving information on a reception candidate antenna group from a plurality of reception nodes;

Wireless communication with the receiving node is performed based on one or more antenna element combinations.

18. The transmitting node of claim 17, wherein each of the one or more antenna element combinations comprises at least one transmit antenna element corresponding to a number of transmit antenna elements available at the same time as a transmit node included in one or more transmit antenna elements in the transmit candidate antenna set and at least one receive antenna element corresponding to a number of receive antenna elements available at the same time as a receive node included in one or more receive antenna elements in the receive candidate antenna set.

19. The transmitting node of claim 17, wherein in performing wireless communication with a receiving node, the processor further causes the transmitting node to perform:

transmitting information about one or more antenna element combinations to a receiving node;

Performing a first measurement procedure with the receiving node based on the information about the one or more antenna element combinations;

identifying reception intensities respectively corresponding to one or more antenna element combinations based on the first measurement procedure; and

Respective priorities of the one or more antenna element combinations are determined based on received strengths respectively corresponding to the one or more antenna element combinations.

20. The transmitting node of claim 19, wherein in determining the first lens, the processor further causes the transmitting node to perform:

identifying Doppler shift DS information and time delay requirement LR information of each receiving node; and

Respective priorities of the one or more antenna element combinations are determined based on reception intensities respectively corresponding to the one or more antenna element combinations, DS information of each reception node, and LR information of each reception node.